Australian scientists say they have developed a blood test to detect melanoma in its early stages.

The test, billed as a world first, is designed to make it easier to spot the skin cancer before it becomes fatal, according to researchers.

Currently, doctors rely on skin examinations and biopsies to detect melanoma, which can spread quickly.

Researchers say the blood test could provide more accurate results than the human eye, and save many lives.

Developed by scientists at Edith Cowan University, the test picks up melanoma by recognising auto-antibodies produced by the body to combat the cancer's early growth.

In a trial involving about 200 people - half of whom had the cancer - the test was successful in 81.5% of cases.

It will now undergo clinical trials, to take place within three years, in a bid to improve its accuracy to 90%. Researchers hope it could be approved for use within five years.

Early detection
Malignant melanoma, the most serious form of skin cancer, is mainly caused by exposure to UV radiation. It often starts with a change in a mole or a new growth on skin.

While specialists are well-trained to spot melanoma, Prof Mel Ziman, head of the research team, said the blood test could hasten diagnosis.

"Often in routine clinical practice, it can be a little difficult to tell an early stage melanoma from a mole," she told the BBC.

"This blood test will fit in when the patient goes to the clinic to determine whether the lesion is a melanoma. The physician could do the test first before feeling like they have to do a biopsy."

The study initially examined 1,627 functional proteins. After analysis, researchers identified 10 auto-antibodies that best indicated the presence of melanoma.

Prof Ziman said detecting melanoma early was critical.

"If we can remove the melanoma when it is less than 1mm thick, you have a 98-99% chance of survival," she said.

"As soon as it spreads further into the skin, survival rates drop dramatically."

Melanoma accounts for the most skin cancer-related deaths, according to the World Health Organization, and is one of the most common cancers for young people.

In Australia, where incidence rates are highest, about 1,500 people die from melanoma each year.

The test will not pick up other types of skin cancers such as squamous cell and basal cell carcinoma, researchers said.

Health experts have urged people to keep checking their skin.

"The false positive and false negative rates of this test mean that the results will need to be interpreted with caution and, where practical, combined with a full skin check by a dermatologist," Prof Rodney Sinclair, a University of Melbourne dermatology expert, told Australian Associated Press.

The research was published in the journal Oncotarget.